US962793A

US962793A - Electric heating unit.

Info

Publication number: US962793A
Application number: US48641909A
Authority: US
Inventors: Herbert M Smith
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1909-03-29
Filing date: 1909-03-29
Publication date: 1910-06-28
Anticipated expiration: 1927-06-28

Description

H. M. SMITH. LEGTRIG HEATING UNIT.

IOATION FILED MAR. 29. 1909.

962,793. Patented June 28,1910.

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Inventor;

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HERBERT M. SMITH, OF PITTSI IELD, MASSACHUSETTS, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC HEATING UNIT.

Specification of Letters Patent. P te -ten June 25, 1910.

Application filed. March 29. 1909.

Serial No. 486,418.

the arrangement being such that the casing is bent around the unit without injury either to the unit or to the metal of the casing.

In carrying out my invention, I employ in connection with a fiat heating unit, a container for the unit which is bent over it in such a way as to hold it'firmly in place. It

has been found necessary to use relatively heavy metal for forming this casing, which requires a hard blow and great pressure to close down. Moreover, in closing down the metal flange around the unit, the great pressure used in the folding operation bruises the mica insulation and renders the insulation imperfect so that short circuits are liable to result. To overcome this objection, I have cut away the metal at the point where the bend occurs, thus grinding a weak line where the shell is to be folded over.

Other obj ects of my invention will appear in the course of the following specification,

in which I have shown my invention embodied in cncrete form for purposes of illustration.

In the accompanying drawings, embodying' my invention, Figure 1 is a sectional plan View of my device; Fig. 2 is a sectional elevation of the same on the line 22; Fig. 3 shows a fragmentary detail of the cupshaped casing; and Fig. 4 shows a fragmentary detail of a modified form...

Referring to the drawings, 10 and 11 represent two sections of a heating unit arranged in the form of concentric rings, one within and spaced from the other. This particular arrangement of heating unit forms no' art of my invention but. I have shown it or purposes of illustration. Furthermore, this particular arrangement of unit is disclosed in an application filed by J. C. Logan, Serial No. 484,692, filed March 20, 1909, and requires no further description aside from the means which I provide for keeping the unit central. within the casing.

Generally speaking, the unit consists of two mica rin s mounted within a cup-shaped casing 12. This casing may be of any desired material,as forinstance, steel or iron. Inorder to hold the outer ring rigidly within the casing so that the wires will not touch the casing, I form projections 13 on the mica at various points around the ring, which engage the casing. The cup-shaped portion 12 is provided with bolts having heads l4;

brazed to the inner side to project into the cup-shaped portion. The inner ring 11 is likewise provided with projecting portions 16 which receive the shanks of the bolts 15 to hold the ring in place. A plate 17 fits snugly into the casing so as to cover the resistance conductor, rings of mica or other

insulating material

18 and 19 being applied to each side of the conductors to insulate and protect them from the casing. In order to bend the cup-shaped casing over the plate 17 without injuring the insulation, I reduce the metal at the bend. In Fig. 3 I have shown the metal reduced by being entirely cut away or counterbored at 20. This cnables the metal to be bent down more easily upon the plate 17, thus closing the parts firmly together without injury. In Fig. 1 I have shown another method of bringing about this result, which consists in forming a V-shaped groove 21 in the casing at a point Where the bend occurs. The ring of insulation 22 is secured to the plate 17 by the bolts 15 as shown, and the terminals of the resistance conductor are brought down to the terminal pins 23, which are mounted in the insulating ring.

While I have shown and described my invention as embodied in concrete form for purposes of illustration, I do not desire to limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the artwithout departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

W hat I claim as new and desire to secure by Letters Patent of the United states, is,

1. An electric heater comprising a fiat heating unitand a cup-shaped container therefor bent over the unit and having the metal reduced at the bend.

2. An electric heater comprising a flat heating unit, a cup-shaped container therefor and a late covering said unit, said container being ent upon the plate and having the metal reduced at the bend.

3. An electric heater comprising a flat heating unit and a container therefor bent over the unit and having the metal reduced at the bend.

4. An electric heater comprising a flat heating unit, a circular container therefor bent over the unit and having the metal reduced at the bend.

5. An electric heater comprising a heating unit, a cup-shaped container therefor bent over the unit and having the metal reduced at the bend.

6. An electric heater comprising a fiat heating unit, a circular cup-shaped container 8. An electric heater comprising a metal casing, a heating element, and mica insulation covering the element having projecting lugs to center the element and its insulation.

In witness whereof, I have hereunto set my hand this 23rd day of March, 1909.

HERBERT M. SMITH.

' Witnesses:

P. A. SMITH, F. G. LARAMEE.